Darker dome

The Ar­chi­tect of the Capi­tol es­ti­mates that by hav­ing in­stalled en­ergy-ef­fi­cient com­fort-con­trol sys­tems and light­ing, in­clud­ing oc­cu­pancy sen­sors that au­to­mat­i­cally turn off lights when they are not needed, they are sav­ing Amer­i­can tax­pay­ers more than $2.2 mil­lion per year.